Electric push-button.



D. E. BLAIR,A

ELECTRIC PUSH BUTTON.

APPLICATION man APR. 10, 1915.

@,MBASQ., Patented oet. 16, 1917.

STATES PATENT @lllhlQE DAW E. BLAIR., 0F MONTREAL, QUEBEC, CANADA,ASSIGNOR TO EDWARDS & ,l

COMPANY, A COEPORATION 0F NEW YORK.

ELECTRIC PUSH-BUTTON.

Specification of Letters Patent. Patented (Dot. lgfi 'il Applicationfiled .april 10, 1915. Serial No. 20,380.

To all whom t may concern:

Be it lruown that l, DAVID E. BLAIR, a subject of the King of GreatBritain, residing at Montreal, in the Province of Quebec and Dominion ofCanada, have invented certain new and useful Improvements in ElectricPush-Buttons, of which the 'following is a full, clear and exactdescription.

This invention relates to electric push buttons, the object being toprovide a device of this character which is especially adapted to beinstalled in street cars iorthe use of passengers in signaling themotorman. The device, however, embodies structural eatureswhich areadvantageous in a push button wherever used, and therefore the use ci myinvention is not coniined to street cars. ln street cars it is a commonpractice to locate the push buttons inthe posts or frames between thewindows and since these posts are usually compound structures consistingorn a main post in which the sashways are formed, and a cap or vfacingstrip which is usually molded 'for ornamental reasons and. beneath whichthe wires leading to the button are housed, it is desirable to devise aconstruction of button which will permitor the ready removal of the capstrip and of the button itself, for purposes ciB inspection, repair, orwhen the interior of the car is to be varnished. For this purpose, thebutton 'l have invented permits of the reinoval of the cap strip fromthe window post without disturbing any part ci the button itself; italso permits ci the entire removal of the button without thedisconnection oi the wires leading thereto, or, if desired, the wiresmay be readily disconnectccl from the hutten without the aid of tools,and the button in its entirety may be removed without disassemhling.'lhe construction also permits of the entire hutten being inserted inits seat in the post and the terminals of the wires thereafter broughtinto association with it without the aid of tools. The details ofconstruction will now h-described in connection with the acco1npanyingdrawing, in which: i

Figure l is a face view ci a portion orl a car window post with the capstrip removed, showing the body of the push button in place andconnected with the wires, the nger-piece being removed from the button;

Fig. 2 is an enlarged section online 2-2 of Fig. 1, and

Fig. 3 is a transverse section of the coinplete window post and throughthe center of the complete button.

The push button consists of a hollow cylindrical body portion l closedat its rear end and open at its front end. in the bottom of the chamberwithin this cylinder, is an annular groove 2 forming a seat for a spring3 and two longitudinal passages 4 and 5 arranged on each side ci theairis and leading rearward into two transverse rectangular passages 6and which extend through the body l and are arranged parallel to eachother as shown by the dotted lines in Fig. l. The linger-piece consistsoi the usual plunger 8 having a flange 9 which rests against the outerend or the spring 3, the linger-piece being normally heldin its extendedposition by said spring and prevented Vfrom being forced. out of `thebody l by a Hanged metal collar l0 enter, respectively, the passages 4:5, `in which they have free play le will ce seen that with thisconstruction, hy push ing upon the nger-piece, the legs o" connector maybe forced through the passages 4 and 5 until they enter the crosspassages 6 and 7, respectively, andvupon the removal of the pressure,the spring forces the fngenpiece outward and withdraws the legs oftheconnector into the normal position shown in the drawings.n y

Each of the passages 6 and 7 is adaptedto receive a sprin contact clip13. r`Fhese clips are provided with folded spring Contact ends la whichrest immediately under the passages 41 and 5 in a position to be struclrby the connector l2 in its forward movement. The outer end of thel clipsconsist of tail pieces l5 to which Jl'le'iespective ends oi:-

the wires 16 and 17 leading to the button are soldered. The openings ofthe passages 6 and 7 through which the spring clips enter are restrictedby humps 17 over which the spring must be i'orced in order to the depththereof being` inst equal to thelength orn thecylindrical body l of thebutton, and the diameter being such as to permit the button to neatly ttherein with sur"- i'icient friction to hold it iirmly in place. |Thewires i6 and i7 extend asvusual along a groove 2l in the tace of thepost 20, which groove leads to the socket or seat i9. The end of suchgroove is, however, enlarged and deepened to 'orm a triangular cavity2l, the bottom of which leads down to the bottom of the socket for thebut ton. This triangular cavity accommodates the tail-pieces l5 of thespring-contacts which are bent at the point where they leave thepassages 6 and 7 to entend outward along 'the inclined face of thecavity. 22 indicates the ornamental cap or 'acing strip which is usuallyapplied to the outer'surface of the post and held in place by screws.7This cap atl the point where the finger-piece of the button is located,is provided with cylindrical holes which are preferably equipped withbushings or escutcheons 23. rlhe linger-piece projects through this holeinto position where it can be easily reached and pressed inward by thefinger. it will be seen that when the button is thus operated, thecircuit through the two wires is closed by the connector l2, the legs ofwhich, respectively, make Contact with the two springs in the passages 6and 7.

lt will now be seen that the cap strip can be removed and replacedwithout disturbing any part of the button; that after the cap strip isremoved, the button can be bodily removed from its socket in the posteither with or without iirst removing the spring contacts from thepassages 6 and 7, and that in order to separate the button from thewires, it is only necessary to pullout the spring terminals from thepassages and this may be done without the aid of tools, the return ofthe contacts being accomplished with equal facility. An advantageousfeature of the button is the fact that the spring terminals attached tothe wires are conned intensa in separate passages or chambers so thatinA case they should become broken, there is no danger oi a shortcircuit. Furthermore, a complete closure of the circuit is insured witheach movement of the button because of the yielding contact terminalswhich permit the connector carried by the linger-piece to move inwarduntil both of its legs are squarely in contact with the springs. rthebutton is simple and cheap to construct, it

is not liable to get out oi order, and is readily installed.

.l claim l ,in combination, a pair of wires having spring contact'terminals permanently secured to the ends of said wires, a push buttoncomprising a body portion having two separate passages therein, saidpair of spring contact terminals tting into said passages and held inposition therein only by the pressure exerted by said terminals upon thewalls of said passage, a iinger-piece for the push button mounted onsaid body portion and carrying a connector for bridgf ing said contactterminals.

2, ln combination, a pair of wires having resilient contact terminalspermanently secured to the ends thereof, a push button having separatepassages therein, said contact terminals being iitted into said passagesand held in position therein only by the engagement of said terminalswith the walls of said passages, a finger-piece for the push buttonmounted on said body portion and -therein adjacent the bottom thereof, apair ci spring Contact terminals positioned within said passages, saidbody portion having two other passages communicating with the said tworst mentioned passages, and a ringer-piece carried by said body portionhaving a two-legged connector, the legs of which are located in saidlast mentioned passages and are adapted to bridge the contact terminals.

ln witness whereof l subscribe my signature, in the presence oi twowitnesses.

@AWD E. BLAH.

Witnesses: n i

@ma Maclean, Fitomnv'r ihm.

